February 2024 Volume 6

EQUIPMENT & TECHNOLOGY

Benefits of Direct from the Forge Intensive Quenching By Michael A. Aronov

Forging and post-forging heat treatment are critical steps in creating high performance steel components. These two important steps create not only geometry but also affect mechanical properties, part quality, cost and production lead time. Driven by customer needs, forgers are constantly striving to reduce lead time, improve quality, and reduce the costs, especially with respect to heating and cooling operations. One way to simultaneously improve efficiency and mechanical properties of steel is to rapidly quench forgings immediately after hot plastic deformation. The High-Temperature, Thermo-Mechanical Treatment (HTTMT) of steel (forging, rolling, extrusion, etc.) immediately followed by rapid quench cooling, improves mechanical properties of steel compared to the conventional HTTM Treatments when parts are cooled to room temperature prior to subsequent heat treatment [1,2] . For example, for AISI 1040 steel, the tensile strength and yield strength increased by more than 20% after HTTMT followed immediately by quenching compared to the conventional forging. The impact properties of material improved by more than double. By immersing forgings in custom designed quench tanks with high volumes of rapidly flowing water, conventional quench distortion and quench cracking are nearly eliminated, improving mechanical properties of steel forgings. This paper summarizes results obtained by IQ Technologies Inc. (IQT) from metallurgical evaluations of forgings that were hardened in IQT’s Direct from the Forge Intensive Quench (DFIQ) processing equipment. The study was conducted under the Forging Industry Association – Department of Defense Manufacturing Consortium (FDMC) Procurement Readiness Optimization - Forging Advanced Systems and Technologies (PRO-FAST) Program sponsored by Defense Logistics Agency [3] . During that program, three forging shops participated in the project: Bula Forge & Machining of Cleveland, Ohio; Welland Forge of Welland, Ontario; and Clifford-Jacobs Forgings of Champaign, Illinois. Forgings of different sizes, weights and geometries and comprised of alloy and plain carbon steels were successfully subjected to the DFIQ process yielding the benefits sought by the forge and the forge’s customers!

Fig. 1: Portable 600-gallon DFIQ system

1. Portable DFIQ Unit Immediately after forging, all components were quenched in a compact, portable 600-gallon DFIQ unit designed and built by IQT (Fig.1). The DFIQ system, mounted on casters, can be readily positioned in a shop adjacent to a forging hammer or press for rapid transfer from the die to the quench tank. The DFIQ unit includes these components: • 600-gallon stainless steel tank; • mechanized loading table to immerse components in the tank; • a variable speed conveyor for moving forgings through the quench bath; • manifolds equipped with engineered nozzles to strip away deleterious vapor barriers and remove heat; • high volume water pump; • mechanism for cleaning the quenchant of scale; • chiller for maintaining the quenchant temperature within tailored cooling ranges; • control system.

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